Re: [PATCH] usb-audio: Rate limit usb_set_interface error reporting

[Chris Down <chris@xxxxxxxxxxxxxx>]

Hi Takashi,

Takashi Iwai writes:
> This patch itself is safe and good to have, so I'm going to take it as
> is.

Thanks!

> But I'm still curious in which code path the problem happens.  That
> is, we should address such unnecessary repeats if possible.  Do you
> have some more data?

Unfortunately not, I've been running with a kernel testing some other mm 
changes recently so haven't had a chance to debug what's going on here. But it 
starts like this:

    [Fri Apr 21 13:21:10 2023] usb 3-7: USB disconnect, device number 39
    [Fri Apr 21 13:21:10 2023] usb 3-7.1: USB disconnect, device number 40
    [Fri Apr 21 13:21:10 2023] usb 3-7.1.1: USB disconnect, device number 42
    [Fri Apr 21 13:21:10 2023] usb 3-7.4: cannot submit urb (err = -19)
    [Fri Apr 21 13:21:10 2023] usb 3-7.4: Unable to submit urb #2: -19 at snd_usb_queue_pending_output_urbs
    [Fri Apr 21 13:21:10 2023] usb 3-7.4: cannot submit urb 0, error -19: no device
    [Fri Apr 21 13:21:10 2023] usb 3-7.4: cannot submit urb 0, error -19: no device
    [Fri Apr 21 13:21:10 2023] usb 3-7.4: cannot submit urb 0, error -19: no device
    [Fri Apr 21 13:21:10 2023] usb 3-7.4: 1:0: usb_set_interface failed (-19)
    [Fri Apr 21 13:21:10 2023] usb 3-7.4: 2:0: usb_set_interface failed (-19)
    [Fri Apr 21 13:21:10 2023] usb 3-7.1.2: USB disconnect, device number 44
    [Fri Apr 21 13:21:10 2023] usb 3-7.1.4: 1:1: usb_set_interface failed (-19)
    [Fri Apr 21 13:21:10 2023] usb 3-7.1.4: 1:1: usb_set_interface failed (-19)
    [Fri Apr 21 13:21:10 2023] usb 3-7.1.4: 1:1: usb_set_interface failed (-19)
    [Fri Apr 21 13:21:10 2023] usb 3-7.1.4: 1:1: usb_set_interface failed (-19)
    [Fri Apr 21 13:21:10 2023] usb 3-7.1.4: 1:1: usb_set_interface failed (-19)
    [Fri Apr 21 13:21:10 2023] usb 3-7.1.4: 1:1: usb_set_interface failed (-19)
    [Fri Apr 21 13:21:10 2023] usb 3-7.1.4: 1:1: usb_set_interface failed (-19)
    [Fri Apr 21 13:21:10 2023] usb 3-7.1.4: 1:1: usb_set_interface failed (-19)
    [... thousands of messages ensue ...]

So it looks like maybe some ordering is not quite right in destruction, perhaps 
only on multi-level USB topologies?

Thanks,

Chris